WASHINGTON — The International Space Station adjusted its orbit March 6 to avoid a close approach by an imaging satellite operated by Satellogic, the latest evidence of growing congestion in low Earth orbit.
NASA said in a March 6 blog post that the Progress MS-22 spacecraft docked to the station fired its thrusters for a little more than six minutes, raising the station’s orbit to move out of the way of what the agency called an Earth observation satellite. According to Roscosmos, the maneuver, lasting 375.8 seconds, changed the station’s velocity by 0.7 meters per second.
NASA spokesperson Sandra Jones told SpaceNews March 7 that the spacecraft would have approached within about 2.7 kilometers of the station without the maneuver. About 20 minutes before the scheduled maneuver controllers received a “green update” about the close approach, meaning there was no risk to the station, but decided to proceed with the maneuver since the Progress’s thrusters were already enabled.
She did not identify the satellite involved in the close approach to the station other than an “Argentine earth observation satellite launched in 2020.” Other sources said the satellite was ÑuSat-17, also called NewSat-17, one of 10 satellites launched in November 2020 by Satellogic, headquartered in Buenos Aires.
A Satellogic spokesperson said late March 7 it received a conjunction data message, or CDM, from the 18th Space Defense Squadron, the Space Force unit that handles space situational awareness activities, about this close approach. However, the company says it was not contacted by NASA about the conjunction.
Jones said that NASA does not generally talk with individual operators about close approaches to the ISS, instead coordinating with U.S. Space Command. “NASA does not communicate with satellite or debris owners regarding maneuvering their objects because NASA’s responsibility is to ensure the International Space Station remains a safe distance away from conjunctions whenever possible.”
Satellogic says that it routinely screens the CDMs it receives and, depending on the probability of a collision, “we either proactively maneuver or coordinate with the other satellite operator to minimize the risk.” The company added that the NewSat satellites can maneuver “as long as they have propellant,” but it was not immediately clear if NewSat-17 was able to do so.
The orbit of NewSat-17 and the other nine satellites launched in 2020 have been gradually decaying, and are now crossing the orbital altitude of the ISS. That is an increasing concern for ISS operations as it and other Earth observation satellites typically operate in higher sun-synchronous orbits that will decay if not actively deorbited at the end of the missions.
The ISS had conducted at least 32 maneuvers to avoid conjunctions with debris as of December 2022, according to data from the NASA Orbital Debris Program Office. That included two maneuvers in June and November 2022 to avoid debris from the November 2021 Russian anti-satellite weapon demonstration that destroyed the Cosmos 1408 satellite.
The March 6 maneuver, NASA said, will not affect upcoming spacecraft going to and from the station. A Crew Dragon spacecraft to conclude the Crew-5 mission to the station is scheduled to undock as soon as March 9. A cargo Dragon spacecraft is set to launch to the station no earlier than March 14.